JP7238084B2 - liquid crystal display - Google Patents

Description

The present disclosure relates to liquid crystal display devices.

2. Description of the Related Art A liquid crystal display device using a display panel including a liquid crystal cell is used as a display such as a television or a monitor. However, a liquid crystal display device has a lower contrast ratio than an organic EL (Electro Luminescence) display device.

Therefore, conventionally, as a technique for improving the contrast ratio of a liquid crystal display device, a technique has been proposed in which two display panels are superimposed and an image is displayed on each display panel (for example, Patent Document 1). This technology displays a color image on the display panel on the front side (observer side) of the two display panels arranged in front and behind, and displays a black-and-white image on the display panel on the back side (backlight side). This is intended to improve the contrast ratio.

In this case, the two display panels are bonded together by a bonding layer such as an optically clear adhesive sheet (OCA: Optically Clear Adhesive) or an optically transparent adhesive resin (OCR: Optically Clear Resin).

JP 2011-076107 A

A display panel of a liquid crystal display device has a liquid crystal cell and a pair of polarizing plates sandwiching the liquid crystal cell. When bonding two such display panels together by OCA, the polarizing plates of the two display panels are bonded together by OCA. At this time, there is a problem that the thickness of the liquid crystal cell becomes uneven and air bubbles enter the interface between the polarizing plate and the OCA, resulting in deterioration of the quality of the displayed image.

The present disclosure has been made to solve such problems, and is a liquid crystal display device capable of suppressing deterioration in the quality of displayed images even when a plurality of display panels are bonded with a bonding layer such as OCA. intended to provide

A first display panel having a first liquid crystal cell and a pair of first polarizing plates sandwiching the first liquid crystal cell, and a second display panel having a second liquid crystal cell and a pair of second polarizing plates sandwiching the second liquid crystal cell and a joining member that joins the first polarizing plate of the first display panel and the second polarizing plate of the second display panel, and at the end of the first display panel and the second display panel , the end of the joining member is located inside the end of the first polarizing plate and the end of the second polarizing plate.

Advantageous Effects of Invention According to the present disclosure, it is possible to realize a liquid crystal display device capable of suppressing degradation in display image quality.

1 is a diagram showing a schematic configuration of a liquid crystal display device according to Embodiment 1; FIG. 1 is a cross-sectional view showing the configuration of a liquid crystal display device according to Embodiment 1; FIG. It is a figure for demonstrating the mode when bonding two display panels together by one thin OCA. It is a figure for demonstrating the mode when bonding two display panels together by one soft OCA. 4 is a diagram for explaining how the first display panel and the second display panel are bonded together by a bonding member in the liquid crystal display device according to the first embodiment; FIG. 3 is a cross-sectional view showing the configuration of a liquid crystal display device according to Modification 1 of Embodiment 1. FIG. FIG. 10 is a diagram showing a state in which one bonding layer is displaced in the bonding member of the liquid crystal display device according to the embodiment; FIG. 9 is a cross-sectional view showing the configuration of a liquid crystal display device according to Modification 2 of Embodiment 1; FIG. 10 is a cross-sectional view showing the configuration of a liquid crystal display device according to Embodiment 2; FIG. 11 is a cross-sectional view showing the configuration of a liquid crystal display device according to a modification of Embodiment 2; FIG. 11 is a partial cross-sectional view of a liquid crystal display device according to Embodiment 3; 11 is an enlarged cross-sectional view of a liquid crystal display device according to Embodiment 3; FIG.

Embodiments of the present disclosure will be described below. It should be noted that each of the embodiments described below is a preferred specific example of the present disclosure. Therefore, the numerical values, shapes, materials, constituent elements, and arrangement positions and connection forms of the constituent elements shown in the following embodiments are examples and are not intended to limit the present disclosure. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest concept of the present disclosure will be described as optional constituent elements.

Each figure is a schematic diagram and is not necessarily strictly illustrated. Therefore, the scales and the like are not always the same in each drawing. In addition, in each figure, the same code|symbol is attached|subjected to the substantially same structure, and the overlapping description is abbreviate|omitted or simplified.

(Embodiment 1)
First, a liquid crystal display device 1 according to Embodiment 1 will be described with reference to FIG. FIG. 1 is a diagram showing a schematic configuration of a liquid crystal display device 1 according to Embodiment 1. As shown in FIG.

The liquid crystal display device 1 is an example of an image display device configured by superimposing a plurality of display panels each including a liquid crystal cell, and displays still images or moving images (video).

As shown in FIG. 1, the liquid crystal display device 1 according to the present embodiment has a plurality of display panels, a first display panel 100 arranged at a position (front side) close to the observer, and a and a second display panel 200 arranged at a position far from the user (rear side).

Furthermore, the liquid crystal display device 1 includes a backlight 300 arranged behind the first display panel 100 and the second display panel 200 . Specifically, the backlight 300 is arranged behind the second display panel 200 .

The first display panel 100 is a main panel and displays an image visually recognized by the user. In this embodiment, the first display panel 100 displays a color image. The first display panel 100 is provided with a first source driver 102 and a first gate driver 103 to display a color image corresponding to an input video signal in a first image display area 101 (active area).

Specifically, a first source FPC 104 on which a first source driver 102 is mounted and a first gate FPC 105 on which a first gate driver 103 is mounted are connected to the liquid crystal cell of the first display panel 100. . The first source FPC 104 and the first gate FPC 105 are connected to electrode terminals of various signal lines of liquid crystal cells in the first display panel 100 by thermocompression using an anisotropic conductive film (ACF), for example. It is

A first circuit board 106 is connected to a portion of the first source FPC 104 opposite to the first display panel 100 side. The first circuit board 106 is a substantially rectangular printed circuit board (PCB), and a plurality of electronic components are mounted on the first circuit board 106 . The first circuit board 106 has a function of transmitting various signals output from the first timing controller 410 to the first source driver 102 mounted on the first source FPC 104 .

When displaying a color image in the first image display area 101 of the first display panel 100 , various signals output from the first timing controller 410 are input to the first source driver 102 and the first gate driver 103 .

The second display panel 200 is a sub-panel arranged behind the first display panel 100 . In the present embodiment, second display panel 200 displays a monochrome image (black-and-white image) corresponding to the color image displayed on first display panel 100 in synchronization with the color image. The second display panel 200 is provided with a second source driver 202 and a second gate driver 203 to display a monochrome image in the second image display area 201 according to the input video signal.

Specifically, a second source FPC 204 on which a second source driver 202 is mounted and a second gate FPC 205 on which a second gate driver 203 is mounted are connected to the liquid crystal cell of the second display panel 200. . The second source FPC 204 and the second gate FPC 205 are connected to electrode terminals of various signal lines of liquid crystal cells in the second display panel 200 by, for example, thermocompression bonding using an anisotropic conductive film.

A second circuit board 206 is connected to a portion of the second source FPC 204 opposite to the second display panel 200 side. The second circuit board 206 is a substantially rectangular printed circuit board (PCB), and a plurality of electronic components are mounted on the second circuit board 206 . The second circuit board 206 has a function of transmitting various signals output from the second timing controller 420 to the second source driver 202 mounted on the second source FPC 204 .

When displaying a monochrome image in the second image display area 201 of the second display panel 200 , various signals output from the second timing controller 420 are input to the second source driver 202 and the second gate driver 203 .

The first image display area 101 and the second image display area 201 have a plurality of pixels arranged in a matrix. The number of pixels in the first image display region 101 and the number of pixels in the second image display region 201 may be the same or different, but the number of pixels in the first image display region in the first display panel 100, which is the main panel, may be different. The number of pixels of 101 should be larger than the number of pixels of the second image display area 201 in the second display panel 200 which is a sub-panel.

In addition, the driving method of the first display panel 100 and the second display panel 200 is, for example, a lateral electric field method such as an IPS (In Plane Switching) method or an FFS (Fringe Field Switching) method, but is not limited thereto. A VA (Vertical Alignment) method, a TN (Twisted Nematic) method, or the like may be used.

The backlight 300 is a light source unit arranged behind the first display panel 100 and the second display panel 200 and emits light toward the first display panel 100 and the second display panel 200 . In the present embodiment, the backlight 300 is a surface light source unit that evenly irradiates flat diffused light (scattered light).

The backlight 300 is, for example, an LED backlight using an LED (Light Emitting Diode) as a light source, but is not limited to this. Moreover, in the present embodiment, the backlight 300 is of a direct type, and a plurality of LEDs are arranged two-dimensionally. For example, a plurality of LEDs are arranged in a matrix along horizontal columns (row direction) and vertical columns (column direction) of pixels. Further, the backlight 300 may have optical members such as a diffusion plate (diffusion sheet) for diffusing light from the light source and a prism sheet for controlling light distribution. Note that the backlight 300 is not limited to a direct type, and may be an edge type.

The liquid crystal display device 1 further includes a first timing controller 410 that controls the first source driver 102 and the first gate driver 103 of the first display panel 100, and a second source driver 202 and the second gate driver 202 of the second display panel 200. A second timing controller 420 that controls the driver 203 and an image processing unit 430 that outputs image data to the first timing controller 410 and the second timing controller 420 are provided.

The image processing unit 430 receives an input video signal Data transmitted from an external system (not shown), performs image processing, outputs first image data DAT1 to the first timing controller 410, and outputs the second image data DAT1 to the first timing controller 410. It outputs the second image data DAT2 to the timing controller 420 . The image processing unit 430 also outputs control signals such as synchronization signals (not shown in FIG. 1) to the first timing controller 410 and the second timing controller 420 . The first image data DAT1 is image data for color display, and the second image data DAT2 is image data for monochrome display.

As described above, in the liquid crystal display device 1 according to the present embodiment, the image is displayed by overlapping the two display panels, the first display panel 100 and the second display panel 200, so that black can be tightened. . Thereby, an image with a high contrast ratio can be displayed.

Further, the liquid crystal display device 1 is, for example, a HDR (High Dynamic Range) compatible television, and by using a backlight capable of performing local dimming control as the backlight 300, a color image with a higher contrast ratio and higher image quality can be obtained. can be displayed.

The first display panel 100 and the second display panel 200 are attached to each other and held together with the backlight 300 by a holding member (frame or chassis) made of metal or resin.

Next, the bonding structure of the first display panel 100 and the second display panel 200 will be described with reference to FIG. FIG. 2 is a cross-sectional view showing the configuration of the liquid crystal display device 1 according to Embodiment 1. As shown in FIG.

As shown in FIG. 2, the liquid crystal display device 1 includes a first display panel 100, a second display panel 200, and a joining member 250 joining the first display panel 100 and the second display panel 200 together.

The first display panel 100 has a first liquid crystal cell 110 and a pair of first polarizing plates 120 sandwiching the first liquid crystal cell 110 .

The first liquid crystal cell 110 includes a first TFT (Thin Film Transistor) substrate 111 , a first opposing substrate 112 facing the first TFT substrate 111 , and a first liquid crystal cell disposed between the first TFT substrate 111 and the first opposing substrate 112 . and a liquid crystal layer 113 . In the present embodiment, the first liquid crystal cell 110 is arranged such that the first opposing substrate 112 is located in front of the first TFT substrate 111 .

The first TFT substrate 111 is a substrate in which a TFT layer (not shown) is formed on a transparent substrate such as a glass substrate. In the TFT layer, TFTs provided corresponding to pixels arranged in a matrix and wirings for driving the TFTs are formed. A pixel electrode for applying a voltage to the first liquid crystal layer 113 is formed on the planarization layer of the TFT layer.

The first opposing substrate 112 is a CF substrate in which a color filter layer is formed as a pixel forming layer on a transparent substrate such as a glass substrate. The pixel formation layer of the first counter substrate 112 has a black matrix (black portion) and color filters (colored portion). The black matrix is formed, for example, in a grid pattern or a stripe pattern, and the black matrix is formed with a plurality of matrix-like openings forming pixels. A color filter is formed in each opening of the black matrix. That is, the black matrix surrounds the color filters. Each color filter is, for example, a color filter for red, a color filter for green, or a color filter for blue. A color filter of each color corresponds to each pixel. Note that an overcoat layer is formed so as to cover the pixel formation layer. Furthermore, an alignment film is formed on the surface of the overcoat layer.

The first liquid crystal layer 113 is sealed between the first TFT substrate 111 and the first opposing substrate 112 . The first liquid crystal layer 113 is sealed, for example, by forming a frame-shaped sealing member along the outer peripheral edges of the first TFT substrate 111 and the first counter substrate 112 . The liquid crystal material of the first liquid crystal layer 113 can be appropriately selected according to the driving method.

The pair of first polarizing plates 120 sandwiching the first liquid crystal cell 110 is the bonding-side first polarizing plate 121 attached to the surface of the first liquid crystal cell 110 on the side of the bonding member 250 (the side of the second liquid crystal cell 210). , and the first polarizing plate 122 on the non-bonding side attached to the surface of the first liquid crystal cell 110 opposite to the bonding member 250 side.

Specifically, the bonding-side first polarizing plate 121 is bonded to the surface of the first TFT substrate 111 of the first liquid crystal cell 110 and bonded to the bonding member 250 . On the other hand, the first polarizing plate 122 on the non-bonding side is attached to the surface of the first opposing substrate 112 of the first liquid crystal cell 110 .

A pair of first polarizing plates 120 (first polarizing plate 121 on the bonding side and first polarizing plate 122 on the non-bonding side) are arranged so that their polarization directions are orthogonal to each other. That is, the pair of first polarizing plates 120 are arranged in crossed Nicols.

Each of the pair of first polarizing plates 120 is a sheet-shaped polarizing film made of, for example, a resin material. In the present embodiment, of the pair of first polarizing plates 120, the first polarizing plate 121 on the bonding side that is bonded to the bonding member 250 includes the polarizer 121a and the light beam that is arranged on the bonding member 250 side of the polarizer 121a. and a diffusion adhesive layer 121b. Each of the polarizer 121a and the light diffusion adhesive layer 121b is supported by, for example, a transparent resin film such as a TAC (Triacetylcellulose) film. On the other hand, of the pair of first polarizing plates 120, the first polarizing plate 122 on the non-bonded side that is not bonded to the bonding member 250 has a polarizer, TAC, etc., like the first polarizing plate 121 on the bonding side. However, it does not have a light diffusion adhesive layer.

In addition, each of the pair of first polarizing plates 120 may include a transparent protective film as the outermost layer. Also, one of the pair of first polarizing plates 120 may include a retardation plate (retardation film).

The second display panel 200 has a second liquid crystal cell 210 and a pair of second polarizing plates 220 sandwiching the second liquid crystal cell 210 .

The second liquid crystal cell 210 includes a second TFT substrate 211 , a second counter substrate 212 facing the second TFT substrate 211 , and a second liquid crystal layer 213 arranged between the second TFT substrate 211 and the second counter substrate 212 . Prepare. In the present embodiment, the second liquid crystal cell 210 is arranged so that the second TFT substrate 211 is located in front of the second counter substrate 212 . may be arranged so as to be located in

The second TFT substrate 211 has the same configuration as the first TFT substrate 111, and is a substrate in which a TFT layer (not shown) is formed on a transparent substrate such as a glass substrate.

The second counter substrate 212 is a substrate in which a pixel forming layer is formed on a transparent substrate such as a glass substrate. The pixel formation layer of the second counter substrate 212 has a black matrix in which a plurality of matrix-shaped openings forming pixels are formed. An overcoat layer is formed to cover the pixel formation layer of the second counter substrate 212 . Furthermore, an alignment film is formed on the surface of the overcoat layer. Further, in the present embodiment, since the second display panel 200 displays a monochrome image, no color filter is formed in the pixel formation layer of the second counter substrate 212 . Therefore, the openings of the black matrix of the pixel forming layer of the second counter substrate 212 are filled with the overcoat layer.

The second liquid crystal layer 213 is sealed between the second TFT substrate 211 and the second counter substrate 212 . The second liquid crystal layer 213 is sealed, for example, by forming a frame-shaped sealing member along the outer peripheral edges of the second TFT substrate 211 and the second counter substrate 212 . The liquid crystal material of the second liquid crystal layer 213 can be appropriately selected according to the driving method.

The pair of second polarizing plates 220 sandwiching the second liquid crystal cell 210 has the same configuration as the first polarizing plate 120, and is attached to the surface of the second liquid crystal cell 210 on the side of the bonding member 250 (the side of the first liquid crystal cell 110). It is composed of a second polarizing plate 221 on the attached bonding side and a second polarizing plate 222 on the non-bonding side attached to the surface of the second liquid crystal cell 210 opposite to the bonding member 250 side.

Specifically, the second polarizing plate 221 on the bonding side is attached to the surface of the second counter substrate 212 of the second liquid crystal cell 210 and bonded to the bonding member 250 . On the other hand, the second polarizing plate 222 on the non-joining side is attached to the surface of the second TFT substrate 211 of the second liquid crystal cell 210 .

A pair of second polarizing plates 220 (second polarizing plate 221 on the bonding side and second polarizing plate 222 on the non-bonding side) are arranged so that their polarization directions are orthogonal to each other. That is, the pair of second polarizing plates 220 are arranged in crossed Nicols.

Each of the pair of second polarizing plates 220 is a sheet-shaped polarizing film made of, for example, a resin material. In the present embodiment, of the pair of second polarizing plates 220, the second polarizing plate 221 on the bonding side that is bonded to the bonding member 250 includes the polarizer 221a and the light that is arranged on the bonding member 250 side of the polarizer 221a. and a diffusion adhesive layer 221b. Each of the polarizer 221a and the light diffusion adhesive layer 221b is supported by, for example, a transparent resin film such as a TAC film. On the other hand, of the pair of second polarizing plates 220, the second polarizing plate 222 on the non-bonded side that is not bonded to the bonding member 250 has a polarizer, TAC, etc., like the second polarizing plate 221 on the bonded side. However, it does not have a light diffusion adhesive layer.

Each of the pair of second polarizing plates 220 may include a transparent protective film as the outermost layer. Also, one of the pair of second polarizing plates 220 may include a retardation plate (retardation film).

The joining member 250 joins the first display panel 100 and the second display panel 200 together. Specifically, the joining member 250 joins the first polarizing plate 121 on the joining side of the first display panel 100 and the second polarizing plate 221 on the joining side of the second display panel 200 . In this embodiment, the bonding member 250 is in contact with the light diffusion adhesive layer 121b of the first polarizing plate 121 on the bonding side and in contact with the light diffusion adhesive layer 221b of the second polarizing plate 221 on the bonding side.

The bonding member 250 includes a first bonding layer 251 bonded to the first polarizing plate 120, a second bonding layer 252 bonded to the second polarizing plate 220, and between the first bonding layer 251 and the second bonding layer 252. and a third bonding layer 253 located at Specifically, the first bonding layer 251 that is the outermost layer of the bonding member 250 is bonded to the bonding-side first polarizing plate 121 of the pair of first polarizing plates 120 . Also, the second bonding layer 252 that is the outermost layer of the bonding member 250 is bonded to the second polarizing plate 221 of the pair of second polarizing plates 220 on the bonding side.

In this embodiment, the bonding member 250 has a three-layer structure of a first bonding layer 251 , a second bonding layer 252 and a third bonding layer 253 . Therefore, the third bonding layer 253 is an intermediate layer sandwiched between the first bonding layer 251 and the second bonding layer 252, which are outermost layers.

Each of the first bonding layer 251, the second bonding layer 252, and the third bonding layer 253 is a bonding sheet made of a film-shaped optically transparent adhesive sheet (OCA), and is made of, for example, an acrylic resin material. . In other words, the bonding member 250 is an adhesive layer for bonding the first display panel 100 and the second display panel 200 together.

In the bonding member 250 configured in this manner, the hardness of the first bonding layer 251 and the second bonding layer 252 is higher than the hardness of the third bonding layer 253 . In other words, the intermediate third bonding layer 253 is softer than the outermost first bonding layer 251 and second bonding layer 252 . In this case, for example, the average molecular weights of the harder first bonding layer 251 and the second bonding layer 252 are 200,000 or more and 1,000,000 or less, and the average molecular weight of the softer third bonding layer 253 is 150,000 or more and 60,000. less than 10,000.

The hardness (hardness) of each bonding layer (first bonding layer 251, second bonding layer 252, third bonding layer 253) of the bonding member 250 is related to the storage elastic modulus of each bonding layer. Specifically, the lower the storage modulus, the lower the hardness, and the higher the storage modulus, the higher the hardness. In the present embodiment, the storage elastic modulus at 23° C. of the hard first bonding layer 251 and the second bonding layer 252 is, for example, 0.1 MPa to 0.5 MPa, and the soft third bonding layer 253 The storage modulus at 23° C. is, for example, 0.06 MPa to 0.1 MPa. The storage elastic modulus of each bonding layer of the bonding member 250 can be measured by, for example, a torsional shear method using a viscoelasticity measuring instrument.

Moreover, in the present embodiment, the film thicknesses of the first bonding layer 251, the second bonding layer 252, and the third bonding layer 253 are all the same. As an example, the film thicknesses of the first bonding layer 251, the second bonding layer 252, and the third bonding layer 253 are equal, and the total film thickness (total thickness) of the bonding member 250 is 300 μm or more.

Next, the effects and the like of the liquid crystal display device 1 according to the present embodiment will be described, including how the technique of the present disclosure was obtained.

When two display panels each having a liquid crystal cell and a pair of polarizing plates sandwiching the liquid crystal cell are bonded together by OCA, the polarizing plates of the two display panels are bonded together by OCA.

For example, as shown in FIG. 3, when bonding the first display panel 100 and the second display panel 200 together with the bonding member 250X, first, as shown in FIG. 3A, the second display panel 200 is prepared. Next, as shown in FIG. 3B, a joining member 250X made of, for example, one OCA is pasted on the second display panel 200, and then, as shown in FIG. The first display panel 100 is pasted on the member 250X.

Here, the surfaces of the first polarizing plate 120 of the first display panel 100 and the second polarizing plate 220 of the second display panel 200 have minute irregularities. Such minute unevenness is generated during the manufacturing process of the polarizing plate or due to surface treatment such as anti-glare treatment.

At this time, if the thickness of the joint member 250X is thin, the joint member 250X does not have flexibility.
The joining member 250X becomes relatively hard.

Therefore, as shown in FIG. 3(d), the first display panel 100 and the second display panel 200 are pressed together via the joining member 250X, and the first display panel 100 and the second display panel 200 are joined together by the joining member 250X. When the first polarizing plate 120 and the second polarizing plate 220 are bonded together, the hard bonding member 250X cannot absorb the minute unevenness of the first polarizing plate 120 and the second polarizing plate 220 .

As a result, the minute unevenness of the first polarizing plate 120 distorts the first TFT substrate 111 (glass substrate) of the first liquid crystal cell 110 . In addition, the minute unevenness of the second polarizing plate 220 distorts the second opposing substrate 212 (glass substrate) of the second liquid crystal cell 210 . As a result, the thickness of the first liquid crystal cell 110 and the thickness of the second liquid crystal cell 210 become uneven, and the quality of the displayed image deteriorates.

Therefore, it is conceivable to use a thick joining member, but OCAs commercially available as joining members generally have a maximum thickness limit, and from the viewpoint of thickness, there are few options for OCA.

On the other hand, if soft OCA is used as the bonding member 250Y, as shown in FIGS. From the end of the second display panel 200, which is the starting point, the air bubbles 500Y are likely to enter the interface between the second polarizing plate 220 and the bonding member 250Y. Note that FIG. 4 shows the end portions of the first display panel 100 and the second display panel 200 .

Next, as shown in FIG. 4(c), the first display panel 100 is pasted on the joining member 250Y. Although not shown, at this time as well, air bubbles may enter the interface between the first polarizing plate 120 and the bonding member 250Y from the end of the first display panel 100 .

As described above, when soft OCA is used as the bonding member 250Y that bonds the first display panel 100 and the second display panel 200, the air bubbles 500Y are formed at the interface between the first display panel 100 or the second display panel 200 and the bonding member 250Y. intrudes, making it easier for air bubbles to occur. Note that the size of the bubble 500Y is, for example, about φ1 mm to φ2 mm.

After that, as shown in FIG. 4(d), the first display panel 100 and the second display panel 200 are pressed together to bond the first display panel 100 and the second display panel 200 together with the bonding member 250Y. At this time, if the air bubble 500Y exists in the image display area (active area), the quality of the displayed image is degraded.

Also, even if the bubble 500Y exists outside the image display area, as shown in FIG. 4D, the bubble 500Y advances inward and enters the image display area due to the application of heat. Of course, if the bubble 500Y exists within the image display area, the application of heat causes the bubble 500Y to advance further toward the central portion of the image display area, making the bubble 500Y conspicuous. This further degrades the quality of the displayed image.

The technology of the present disclosure has been made based on such findings, and as a result of extensive studies by the inventors of the present application, the joining member 250 that joins the first display panel 100 and the second display panel 200 has material physical properties. It has been found that by adjusting the hardness of each layer by adjusting the hardness of each layer, it is possible to suppress the deterioration of the quality of the displayed image due to the unevenness of the thickness of the liquid crystal cell and the entrapment of air bubbles.

Specifically, in the liquid crystal display device 1 according to the present embodiment, as shown in FIG.
00, the second bonding layer 252 bonded to the second polarizing plate 220 of the second display panel 200, the first bonding layer 251 and the second bonding layer 252 , and the hardness of the first bonding layer 251 and the second bonding layer 252 is set higher than that of the third bonding layer 253 .

Accordingly, even if the surfaces of the first polarizing plate 120 of the first display panel 100 and the second polarizing plate 220 of the second display panel 200 have minute unevenness, the first liquid crystal cell 110 and the second liquid crystal cell 210 It is possible to suppress the occurrence of unevenness in the thickness of the film. Furthermore, it is possible to prevent air bubbles from entering between the first display panel 100 or the second display panel 200 and the bonding member 250 .

This point will be described in detail with reference to FIG. FIG. 5 is a diagram for explaining how the first display panel 100 and the second display panel 200 are bonded together by the bonding member 250 in the liquid crystal display device 1 according to the first embodiment. Note that FIG. 5 shows an enlarged cross-sectional view of a joint portion between the first display panel 100 and the second display panel 200 in the liquid crystal display device 1 .

When bonding the first display panel 100 and the second display panel 200 together with the bonding member 250, first, as shown in FIG. 5A, the second display panel 200 is prepared.

Next, as shown in FIG. 5B, a joining member 250 is pasted onto the second display panel 200. Then, as shown in FIG. At this time, the second bonding layer 252 , the third bonding layer 253 , and the first bonding layer 251 are laminated one by one on the second display panel 200 in this order. Specifically, first, the second bonding layer 252 is bonded onto the second polarizing plate 220 (second polarizing plate 221 on the bonding side) of the second display panel 200, and then the second bonding layer 252 is bonded. Then, the first bonding layer 251 is bonded on the third bonding layer 253 .

Next, as shown in FIG. 5C, the first display panel 100 is attached onto the bonding member 250. Then, as shown in FIG. After that, as shown in FIG. 5D, the first display panel 100 and the second display panel 200 are pressed together to join the first display panel 100 and the second display panel 200 with the joining member 250 .

At this time, the first bonding layer 251 bonded to the first polarizing plate 120 of the first display panel 100 and the second bonding layer 252 bonded to the second polarizing plate 220 of the second display panel 200 among the bonding members 250 is made of hard material. This can prevent air bubbles from entering the interface between the first display panel 100 or the second display panel 200 and the bonding member 250 .

In addition, since the soft third bonding layer 253 is used as a part of the bonding member 250, even if the first bonding layer 251 and the second bonding layer 252 are made of a hard material, the first bonding layer 250 can be bonded to the first bonding layer 250 via the bonding member 250. When the display panel 100 and the second display panel 200 are pressed against each other, the third bonding layer 253 can absorb minute irregularities of the first polarizing plate 120 and the second polarizing plate 220 . In other words, by deforming the soft and flexible third bonding layer 253, the stress from the minute unevenness of the first polarizing plate 120 and the second polarizing plate 220 due to the pressing of the first display panel 100 and the second display panel 200 is reduced. can be absorbed.

As a result, the first TFT substrate 111 of the first liquid crystal cell 110 is distorted by the minute unevenness of the first polarizing plate 120, and the second opposing substrate 212 of the second liquid crystal cell 210 is distorted by the minute unevenness of the second polarizing plate 220. Therefore, it is possible to suppress unevenness in the thickness of the first liquid crystal cell 110 and the second liquid crystal cell 210 .

Also, when the soft third bonding layer 253 is bonded onto the second bonding layer 252, air bubbles may enter between the second bonding layer 252 and the third bonding layer 253. Since the hard first bonding layer 251 is bonded onto the third bonding layer 253, air bubbles that have entered between the second bonding layer 252 and the third bonding layer 253 can be defoamed.

Note that in the present embodiment, when bonding the bonding member 250 to the second display panel 200 , the first bonding layer 251 , the second bonding layer 252 and the third bonding layer 253 are laminated on the second display panel 200 . Although the sheets are pasted one by one, the present invention is not limited to this. For example, the first bonding layer 251, the second bonding layer 252, and the third bonding layer 253 are first bonded together to form one integrated bonding member 250 in advance. 2 may be attached to the display panel 200 . In this case as well, since the hard first bonding layer 251 and the second bonding layer 252 are present in the bonding member 250, when bonding the first display panel 100 and the second display panel 200 together with the bonding member 250, the first bonding layer 251 and the second bonding layer 252 are hard. Intrusion of air bubbles between the display panel 100 or the second display panel 200 and the bonding member 250 can be suppressed. In addition, since the soft third bonding layer 253 is present in the bonding member 250, when the first display panel 100 and the second display panel 200 are pressed through the bonding member 250, the first polarizing plate 120 and the second display panel 200 are pressed together. The third bonding layer 253 can absorb fine unevenness of the second polarizing plate 220 .

In this way, the bonding member 250 for bonding the first display panel 100 and the second display panel 200 is configured such that the third bonding layer 253 made of a soft material is sandwiched between the first bonding layer 251 and the second bonding layer 252 made of a hard material. As a result, the thicknesses of the first liquid crystal cell 110 and the second liquid crystal cell 210 are uneven, and air bubbles enter the interface between the two members between the first display panel 100 and the second display panel 200. can be suppressed. Therefore, it is possible to suppress deterioration in the quality of the display image.

The film thickness of the bonding member 250 is preferably 300 μm or more, for example. As a result, the bonding member 250 can effectively absorb the minute unevenness of the first polarizing plate 120 and the second polarizing plate 220, so that the thickness unevenness of the first liquid crystal cell 110 and the second liquid crystal cell 210 can be effectively reduced. can be suppressed.

As described above, according to the liquid crystal display device 1 according to the present embodiment, it is possible to suppress deterioration in the quality of the displayed image.

Further, in the present embodiment, the thickness of each of the three bonding layers (first bonding layer 251, second bonding layer 252, and third bonding layer 253) in bonding member 250 is the same. The thickness can be different.

In this case, the thickness of the flexible third bonding layer 253 is preferably greater than the thickness of the first bonding layer 251 and the thickness of the second bonding layer 252 . For example, as in a liquid crystal display device 1A according to Modification 1 of Embodiment 1 shown in FIG. is d2, and the thickness of the third bonding layer 253 is d3, d3>d1 and d3>d2.

In this case, the total film thickness of the bonding member 250A in this modification (FIG. 6) is the same as the total film thickness of the bonding member 250 in Embodiment 1, but the bonding member 250A in this modification Third bonding layer 253, which is an intermediate layer, is thicker than bonding member 250 in the embodiment. Further, in this modified example, the film thickness of the third bonding layer 253 is increased while maintaining the total film thickness of the bonding member 250A.

By increasing the thickness of the soft third bonding layer 253 in this way, the microscopic unevenness of the surfaces of the first polarizing plate 120 and the second polarizing plate 220 is reduced compared to the liquid crystal display device 1 in the first embodiment. easier to absorb. Thereby, unevenness in thickness of the first liquid crystal cell 110 and the second liquid crystal cell 210 can be further suppressed. In addition, by increasing the thickness of the third bonding layer 253 without increasing the total film thickness of the bonding member 250A, the thickness of the bonding member 250A can be increased without waste. 2, unevenness in the thickness of the liquid crystal cell 210 can be suppressed. As a result, a thin liquid crystal display device 1A with high image quality can be realized.

In addition, in the present embodiment, the bonding member 250 has a laminated structure of three bonding layers (first bonding layer 251, second bonding layer 252, and third bonding layer 253). The second bonding layer 252 and the third bonding layer 253 have the same length (width).

In this case, at the end of the joining member 250, the end of the first joining layer 251, the end of the second joining layer 252, and the end of the third joining layer 253 may be shifted. At this time, when sequentially bonding the first bonding layer 251, the second bonding layer 252, and the third bonding layer 253, the end portion of the first bonding layer 251, the end portion of the second bonding layer 252, and the third bonding layer The edge of the layer 253 may be intentionally shifted, or the edge of the first bonding layer 251, the edge of the second bonding layer 252, and the edge of the third bonding layer 253 may be unintentionally misaligned. The ends may be offset.

However, the edge of the first bonding layer 251, the edge of the second bonding layer 252, and the edge of the third bonding layer 253 are too misaligned, and as shown in FIG. 252 and the third bonding layer 253 protrude from the other end, and part of the ends of the first bonding layer 251, the second bonding layer 252, and the third bonding layer 253 protrude from the other end. is covered, there is a risk that air bubbles may be caught in the end portion of the joining member 250 .

Therefore, as in the liquid crystal display device 1B shown in FIG. , should be shifted stepwise.

Specifically, in FIG. 8, from the second display panel 200 toward the first display panel 100, the length (width) of the second bonding layer 252, the length (width) of the third bonding layer 253, and the first By sequentially decreasing the length (width) of the bonding layer 251, the end portion of the bonding member 250B is made stepped.

As a result, when the first bonding layer 251, the second bonding layer 252, and the third bonding layer 253 are sequentially bonded together, the ends of the first bonding layer 251, the second bonding layer 252, and the third bonding layer 253 do not protrude. can be suppressed. Therefore, it is possible to suppress air bubbles from being caught in the end portion of the joining member 250, thereby suppressing deterioration in the quality of the display image.

Further, at the end portion of the bonding member 250B shown in FIG. 8, the amount of deviation W of the steps of the first bonding layer 251, the second bonding layer 252, and the third bonding layer 253 (stepping portion of the stairs) is 200 μm or more and 400 μm or less. should be That is, the amount of deviation between the end of the first bonding layer 251 and the end of the third bonding layer 253 and the amount of deviation between the end of the third bonding layer 253 and the end of the second bonding layer 252 are 200 μm or more and 400 μm or less. should be

The bonding accuracy of one bonding layer such as OCA is about 100 μm. Therefore, by setting the displacement amount W of the steps of the first bonding layer 251, the second bonding layer 252, and the third bonding layer 253 to 200 μm to 400 μm, even if bonding misalignment occurs, the first bonding layer 251 , part of the ends of the second bonding layer 252 and the third bonding layer 253 do not cover the other ends. As a result, it is possible to reliably prevent air bubbles from being caught in the end portion of the joint member 250 .

In addition, the stepped portion at the end of the joining member 250B is preferably located outside the image display areas (active areas) of the first display panel 100 and the second display panel 200 . Specifically, the stepped portion at the end of the joining member 250B is formed at a position overlapping the frame area of the black matrix that serves as the boundary between the image display areas of the first display panel 100 and the second display panel 200. Good. Also, in this case, the stepped portion at the end of the joining member 250B can be formed at a position overlapping the intermediate frame that holds the first display panel 100 and the second display panel 200 .

In this way, by positioning the stepped portion at the end of the joint member 250B outside the image display regions (active regions) of the first display panel 100 and the second display panel 200, the stepped portion at the end of the joint member 250B is formed. Even if foreign matter such as dust adheres to the shaped portion, deterioration of the quality of the display image can be suppressed.

Also, the shape of the end portion of the joining member 250B may be processed in accordance with the shape of the stairs. For example, when a bonding layer such as OCA is individually punched out from a large sheet using a punching blade, the adhesive resin dripping on the end surface of the bonding layer is removed or the end surface of the bonding layer is flattened when the punching blade is pulled out. Therefore, it is preferable to cut the end surface of the bonding layer after punching. Alternatively, instead of using a punching blade, the end surface of the bonding layer may be made flat by punching the bonding layer out of the large sheet by laser cutting.

8, from the second display panel 200 toward the first display panel 100, the length (width) of the second bonding layer 252, the length (width) of the third bonding layer 253, and the first bonding layer 251 By gradually decreasing the length (width) of the joint member 250B, the end portion of the joint member 250B has a stepped shape, but the present invention is not limited to this. For example, from the first display panel 100 toward the second display panel 200, the length (width) of the first bonding layer 251, the length (width) of the third bonding layer 253, and the length (width) of the second bonding layer 252 ( Width) may be gradually reduced to form a stepped end portion of the bonding layer 250B.

(Embodiment 2)
Next, a liquid crystal display device 1C according to Embodiment 2 will be described with reference to FIG. FIG. 9 is a cross-sectional view showing the configuration of a liquid crystal display device 1C according to the second embodiment.

As shown in FIG. 9, a liquid crystal display device 1C according to the present embodiment has a three-layer structure in which a first display panel 100 and a second display panel 200 are joined together, similarly to the liquid crystal display device 1 according to the first embodiment. is provided with a joint member 250C.

Specifically, bonding member 250C in the present embodiment includes first bonding layer 251C bonded to first polarizer 120 of first display panel 100 and second polarizer 220 of second display panel 200. and an intermediate layer (third layer) 253C positioned between the first bonding layer 251C and the second bonding layer 252C.

The liquid crystal display device 1C according to the present embodiment and the liquid crystal display device 1 according to the above-described embodiment are different in hardness between the three bonding layers constituting the bonding member. Specifically, in the bonding member 250 according to the first embodiment, the hardness of the first bonding layer 251 and the second bonding layer 252 is higher than the hardness of the intermediate layer 253. In the member 250C, the hardness of the first bonding layer 251C and the second bonding layer 252C is softer than the hardness of the intermediate layer 253C. That is, in the bonding member 250C of the present embodiment, the intermediate layer 253C is harder than the first bonding layer 251C and the second bonding layer 252C.

In the joining member 250C of the present embodiment, each of the first joining layer 251C, the second joining layer 252C and the intermediate layer 253C is a joining sheet made of film-like OCA. For example, the third bonding layer 253 of the bonding member 250 in Embodiment 1 can be used as the first bonding layer 251C and the second bonding layer 252C that are soft OCA. Further, as the intermediate layer 253C made of hard OCA, the first bonding layer 251 or the second bonding layer 252 of the bonding member 250 in the first embodiment can be used. In this case, the intermediate layer 253C becomes the third bonding layer. The thickness of the intermediate layer 253C is preferably thicker than the thickness of the first bonding layer 251C and the thickness of the second bonding layer 252C, but the thickness is not limited to this.

Thus, by bonding the first display panel 100 and the second display panel 200 together using the bonding member 250C in which the intermediate layer 253C is harder than the first bonding layer 251C and the second bonding layer 252C, , air bubbles can be prevented from entering the interface between the two members between the first display panel 100 and the second display panel 200 .

For example, when the first bonding layer 251C, the second bonding layer 252C, and the intermediate layer 253C are sequentially bonded one by one as in the first embodiment, first, a soft second bonding layer is placed on the second display panel 200. Even if air bubbles enter between the second display panel 200 and the second bonding layer 252C when the layer 252C is bonded together, the hard intermediate layer 253C is then bonded onto the second bonding layer 252C. Therefore, it is possible to remove air bubbles that have entered between the second display panel 200 and the second bonding layer 252C. After that, even if air bubbles enter between the intermediate layer 253C and the first bonding layer 251C when the first bonding layer 251C is adhered onto the intermediate layer 253C, a hard layer is then placed on the first bonding layer 251C. Since the first display panel 100 is bonded together, air bubbles that have entered between the intermediate layer 253C and the first bonding layer 251C can be defoamed.

When bonding the bonding member 250C to the second display panel 200, instead of sequentially bonding the first bonding layer 251, the second bonding layer 252, and the intermediate layer 253C one by one, the first bonding layer 251C, the The first display panel 100 and the second display panel 200 may be bonded together using one bonding member 250C in which the two bonding layers 252C and the intermediate layer 253C are integrated in advance. In this case as well, since the hard intermediate layer 250C is present in the bonding member 250C, when the first display panel 100 and the second display panel 200 are bonded together by the bonding member 250C, the first display panel 100 or the second display panel 200 is hard. It is possible to prevent air bubbles from entering between the second display panel 200 and the joint member 250C.

Furthermore, in the present embodiment as well, since the soft first bonding layer 251C and the second bonding layer 252C are present in the bonding member 250C, the first polarizing plate 120 and the second polarizing plate 220 are arranged in the same manner as in the first embodiment. can be absorbed by the intermediate layer 253C. Accordingly, it is possible to suppress unevenness in the thickness of the first liquid crystal cell 110 and the second liquid crystal cell 210 due to the fine unevenness of the first polarizing plate 120 and the second polarizing plate 220 .

As described above, in the liquid crystal display device 1C of the present embodiment, the bonding member 250C for bonding the first display panel 100 and the second display panel 200 is formed by connecting the intermediate layer 253C made of a hard material to the first bonding layer 251C made of a soft material and the second bonding layer 251C. It is configured to be sandwiched between two bonding layers 252C. As a result, it is possible to prevent air bubbles from entering the interface between the two members between the first display panel 100 and the second display panel 200, and to prevent unevenness in the thickness of the first liquid crystal cell 110 and the second liquid crystal cell 210. can be suppressed. Therefore, it is possible to suppress deterioration in the quality of the display image.

Further, although intermediate layer 253C in the present embodiment is made of resin, intermediate layer 253C is preferably made of glass, which is a harder material than resin. In this case, a glass plate can be used as the intermediate layer 253C.

Accordingly, it is possible to prevent air bubbles from remaining at the interface between the two members between the first display panel 100 and the second display panel 200 .

Further, in the bonding member 250C in the liquid crystal display device 1C shown in FIG. Although the end portions of the second bonding layer 252C and the intermediate layer 253C are flush with each other, the present invention is not limited to this.

For example, at the end of the joint member 250C, the end of the first joint layer 251C, the end of the second joint layer 252C, and the end of the intermediate layer 253C may be misaligned. Specifically, the length (width) of the second bonding layer 252C, the length (width) of the intermediate layer 253C, and the length (width) of the first bonding layer 251C are sequentially decreased or increased. , the end of the joint member 250C may be stepped.

As a result, when the first bonding layer 251C, the second bonding layer 252C, and the intermediate layer 253C are successively bonded together, the ends of the first bonding layer 251C, the second bonding layer 252C, and the intermediate layer 253C can be prevented from protruding. Therefore, it is possible to suppress air bubbles from being caught in the end portion of the joint member 250C, thereby suppressing deterioration in the quality of the display image.

Further, as in the liquid crystal display device 1D shown in FIG. 10, at the end of the bonding member 250D, the end of the hard intermediate layer 253C is softer than the end of each of the first bonding layer 251C and the second bonding layer 252C. It should be prominent. For example, the length of the intermediate layer 253C may be longer than the length of the first bonding layer 251C and the length of the second bonding layer 252C.

With this configuration, even when the first bonding layer 251C, the second bonding layer 252C, and the intermediate layer 253C are sequentially bonded one by one, the first bonding layer 251C, the second bonding layer 252C, and the intermediate layer 253C are integrated. Even when the joint members 250C are bonded together, the end portions of the soft joint layers (the first joint layer 251C and the second joint layer 252C) do not protrude from the end portions of the other joint layers and hang down. It is possible to suppress entrainment of air bubbles at the edge of the sagging bonding layer.

In FIG. 10, the end of the intermediate layer 253C protrudes from the end of the first joining layer 251C and the end of the second joining layer 252C over the entire circumference of the joining member 250C, but the present invention is not limited to this. For example, in the case of the bonding member 250C having a rectangular planar shape, the end portions of the intermediate layer 253C are the ends of the first bonding layer 251C and the second bonding layer 252C on one, two, or three of the four sides. It is sufficient if it protrudes from the end of the In this case, the end of the intermediate layer 253C preferably protrudes from the end of the first bonding layer 251C and the end of the second bonding layer 252C on one or two sides in the bonding direction.

(Embodiment 3)
Next, a liquid crystal display device 1E according to Embodiment 3 will be described with reference to FIGS. 11 and 12. FIG. FIG. 11 is a partial cross-sectional view of a liquid crystal display device 1E according to the third embodiment. 12 is an enlarged sectional view of FIG. 11. FIG. 11 and 12 show the end on the gate driver side where the first gate FPC 105 and the second gate FPC 205 are provided.

As shown in FIGS. 11 and 12, the liquid crystal display device 1E includes a first display panel 100, a second display panel 200, a joining member 250E for joining the first display panel 100 and the second display panel 200, a back A light 300 and a frame 600 are provided. The structures of the backlight 300 and the frame 600 in this embodiment can also be applied to the first and second embodiments.

The frame 600 is a holding member that holds the first display panel 100 , the second display panel 200 and the backlight 300 . In this embodiment, the frame 600 is composed of an upper frame 610 (first frame), a middle frame 620 (second frame), and a lower frame 630 (third frame).

The first display panel 100 and the second display panel 200 have the same configurations as in the first and second embodiments. Therefore, the first display panel 100 includes a first liquid crystal cell 110 having a first TFT substrate 111, a first counter substrate 112, and a first liquid crystal layer 113, and a pair of first polarizing plates 120 sandwiching the first liquid crystal cell 110. Prepare.

The first liquid crystal layer 113 includes a first TFT substrate 111 and a first counter substrate 112 as a pair of first substrates, and a first sealing member 114 for sealing the first liquid crystal layer 113 between the pair of first substrates. have. For example, the first sealing member 114 is formed in a frame shape along the outer peripheral edges of the first TFT substrate 111 and the first counter substrate 112 . As an example, the width of the first sealing member 114 is about 1 to 2 mm, but the width is not limited to this.

The first liquid crystal cell 110 also has a first peripheral light shielding layer 115 formed in a peripheral area of the first image display area 101 (active area). The first peripheral light shielding layer 115 is formed on the first opposing substrate 112 . The first peripheral light shielding layer 115 can be made of the same material as the black matrix formed in the first image display area 101, for example.

The second liquid crystal layer 213 includes a second TFT substrate 211 and a second counter substrate 212 as a pair of second substrates, and a second sealing member 214 for sealing the second liquid crystal layer 213 between the pair of second substrates. have. For example, the second sealing member 214 is formed in a frame shape along the outer peripheral edges of the second TFT substrate 211 and the second counter substrate 212 . As an example, the width of the second sealing member 214 is the same as the width of the first sealing member 114, which is about 1 to 2 mm, but the width is not limited to this.

In this embodiment, the second sealing member 214 is formed outside the first sealing member 114 of the first liquid crystal cell 110 . Specifically, the outer end of the second sealing member 214 is positioned further outward than the outer end of the first sealing member 114, and the inner end of the second sealing member 214 is positioned further outward than the outer end of the first sealing member 114. is located outside the inner end of the first sealing member 114 .

The second liquid crystal cell 210 also has a second peripheral light shielding layer 215 formed in a peripheral area of the second image display area 201 (active area). The second peripheral light shielding layer 215 is formed on the second opposing substrate 212 . The second peripheral light shielding layer 215 can be made of the same material as the black matrix formed in the second image display area 201, for example.

In this embodiment, the second peripheral light shielding layer 215 is formed outside the first peripheral light shielding layer 115 of the first liquid crystal cell 110 . Specifically, the outer edge of the second peripheral light-shielding layer 215 is positioned further outward than the outer edge of the first peripheral light-shielding layer 115, and the inner edge of the second peripheral light-shielding layer 215 is located outside the inner edge of the first peripheral light shielding layer 115 . In this way, by positioning the inner edge of the second peripheral light-shielding layer 215 further outward than the inner edge of the first peripheral light-shielding layer 115, the display screen of the liquid crystal display device 1E is obliquely viewed. Therefore, it is possible to prevent the image quality of the end portion of the display image from appearing to be poor.

The backlight 300 has a plurality of LEDs 310 , a transparent substrate 320 , an optical sheet 330 and a reflector 340 .

Each of the plurality of LEDs 310 is an example of a light emitting element. As the LED 310, for example, a white LED light source that emits white light can be used. In the present embodiment, backlight 300 is a direct backlight, and multiple LEDs 310 are arranged two-dimensionally. Specifically, the plurality of LEDs 310 are arranged in a matrix on the bottom of the body portion 631 of the lower frame 630 . In this embodiment, the plurality of LEDs 310 are arranged on the bottom surface of the reflector 340 arranged in the recess of the lower frame 630 .

A transparent substrate 320 and an optical sheet 330 are arranged in front of the LED 310 (on the light emitting side). That is, the transparent substrate 320 and the optical sheet 330 are opposed to the body portion 631 of the lower frame 630 .

The transparent substrate 320 is, for example, a glass plate transparent to visible light. In this case, as the transparent substrate 320, tempered glass having excellent mechanical strength may be used. By using a glass plate as the transparent substrate 320 in this way, it is possible to realize the transparent substrate 320 that has little expansion or contraction due to heat and has high rigidity.

The transparent substrate 320 is supported by the supporting portion 632 of the lower frame 630 at its outer peripheral edge. Specifically, the outer peripheral edge of the transparent substrate 320 is placed on the flange portion of the reflector 340 placed on the support portion 632 .

The optical sheet 330 is arranged in front of the LEDs 310 (on the light emitting side). In this embodiment, the optical sheet 330 is attached to the front surface of the transparent substrate 320 . The optical sheet 330 imparts an optical effect to light emitted from the LEDs 310 . As the optical sheet 330, for example, a diffusion plate (diffusion sheet) and/or a prism sheet for diffusing the light from the LEDs 310 can be used. The optical sheet 330 is a resin sheet made of, for example, a resin material. The number of optical sheets 330 may be one, or may be plural.

The reflector 340 has a function of reflecting light from the plurality of LEDs 310 . The reflector 340 is arranged on the bottom of the main body 631 of the lower frame 630 . The reflector 340 is made of a thin metal plate such as a steel plate or an aluminum plate. In this case, the surface of the reflector 340 is preferably painted white. Note that the reflector 340 may be made of a white resin material.

As described above, frame 600 is composed of upper frame 610 , middle frame 620 , and lower frame 630 . The upper frame 610, the middle frame 620 and the lower frame 630 are fixed to each other by screws, for example.

The upper frame 610 which is the first frame is a front frame arranged on the upper side of the frame 600 . In the present embodiment, the upper frame 610 is a metal frame having a rectangular frame shape in plan view and an L-shaped cross section, and is made of a highly rigid metal material such as a steel plate or an aluminum plate. As an example, the upper frame 610 can be formed by subjecting a metal plate cut into a predetermined shape to press work such as bending.

The upper frame 610 has a first bezel portion 611 covering the peripheral portion of the first display panel 100 and first sidewall portions 612 extending from the first bezel portion 611 toward the lower frame 630 side. The first bezel portion 611 protrudes like a flange from the upper end of the first side wall portion 612 and is formed in a frame shape so as to cover the entire periphery of the outer peripheral edge of the surface of the first display panel 100 .

Middle frame 620 , which is the second frame, is a middle frame arranged between upper frame 610 and lower frame 630 . The middle frame 620 supports the first display panel 100 and the second display panel 200 from the backlight 300 side. In this embodiment,
The middle frame 620 is a metal frame having a rectangular frame shape in plan view and an L-shaped cross section, and is made of a highly rigid metal material such as a steel plate or an aluminum plate. As an example, the middle frame 620 can be formed by subjecting a metal plate cut into a predetermined shape to press work such as bending.

The middle frame 620 has a second bezel portion 621 covering the peripheral portion of the second display panel 200 and a second side wall portion 622 extending from the second bezel portion 621 toward the lower frame 630 side. The second bezel portion 621 protrudes like a flange from the upper end of the second side wall portion 622 and is formed in a frame shape so as to cover the entire periphery of the outer peripheral edge of the back surface of the second display panel 200 .

A lower frame 630 which is a third frame is a rear frame arranged on the rear side of the frame 600 . In the present embodiment, the lower frame 630 is a metal housing formed in a concave shape as a whole, and is made of a highly rigid metal material such as a steel plate or an aluminum plate.

The lower frame 630 has a body portion 631 that accommodates the LEDs 310 of the backlight 300 therein, and a support portion 632 that supports the transparent substrate 320 and the reflector 340 of the backlight 300 .

In the liquid crystal display device 1E configured in this manner, the first display panel 100 and the second display panel 200 are joined by the joining member 250E, as in the liquid crystal display device 1 in the first embodiment. Unlike the joint member 250 in the first embodiment, the joint member 250E in the embodiment has a single-layer structure and may be composed of only one OCA.

In this embodiment, the joint member 250E is made of a soft material. For example, the bonding member 250E is as soft as the third bonding layer 253 of the bonding member 250 in the first embodiment. The joint member 250E is made of, for example, an acrylic resin material.

Also, the joining member 250E has a thickness of, for example, 300 μm or more.

In this way, since the bonding member 250E is made of thick and soft OCA, the bonding member 250E absorbs fine unevenness of the first polarizing plate 120 and the second polarizing plate 220, as in the first embodiment. be able to. Accordingly, it is possible to suppress unevenness in the thickness of the first liquid crystal cell 110 and the second liquid crystal cell 210 due to the fine unevenness of the first polarizing plate 120 and the second polarizing plate 220 .

On the other hand, since the joint member 250E is composed only of soft OCA, when the first display panel 100 and the second display panel 200 are adhered together by the joint member 250E, the end portion of the joint member 250E does not adhere to the first display panel. Air bubbles may enter between the 100 and the joint member 250E or between the second display panel 200 and the joint member 250E. For example, if the edge of the bonding member 250E protrudes beyond the edge of the first polarizing plate 120 of the first display panel 100 and the edge of the second polarizing plate 220 of the second display panel 200, the bonding member 250E There is a possibility that the end portion may droop toward the first polarizing plate 120 or the second polarizing plate 220, and air bubbles may enter between the first polarizing plate 120 or the second polarizing plate 220 and the bonding member 250E. As a result, the air bubbles may enter the active area and degrade the quality of the displayed image.

Moreover, when the end of the bonding member 250E hangs, the adhesive layer component (acrylic acid, etc.) There is a possibility that the first polarizing plate 120 or the second polarizing plate 220 may deteriorate by entering the interface with the second liquid crystal cell 210 . As a result, the quality of the displayed image may deteriorate.

Therefore, in the liquid crystal display device 1E of the present embodiment, the end (P _OCA ) of the bonding member 250E is aligned with the end of the first polarizing plate 120 at any end of the first display panel 100 and the second display panel 200. portion (P _POL ) and the end portion (P _POL ) of the second polarizing plate 220 . That is, the end of the bonding member 250E is positioned closer to the active region (first image display region 101, second image display region 201) than the end of the first polarizing plate 120 and the end of the second polarizing plate 220. ing.

In this way, since the end (P _OCA ) of the bonding member 250E is located inside the end (P _POL ) of the first polarizing plate 120 and the end (P _POL ) of the second polarizing plate 220, , when the first display panel 100 and the second display panel 200 are bonded together by the bonding member 250E, air bubbles are prevented from entering between the first polarizing plate 120 or the second polarizing plate 220 and the bonding member 250E. be able to.

Further, when the end (P _OCA ) of the bonding member 250E is located inside the end (P _POL ) of the first polarizing plate 120 and the end (P _POL ) of the second polarizing plate 220, the bonding member The end of 250E does not sag. As a result, the component of the adhesive layer at the end of the bonding member 250E enters the interface between the first polarizing plate 120 and the first liquid crystal cell 110 or the interface between the second polarizing plate 220 and the second liquid crystal cell 210, Deterioration of the polarizing plate 120 or the second polarizing plate 220 can be suppressed.

As described above, in the liquid crystal display device 1E of the present embodiment, the end (P _OCA ) of the bonding member 250E is the end (P POL ) of the first polarizing plate 120 and the end (P _POL ) of the second polarizing plate 220 . _POL ), it prevents air bubbles from entering the periphery of the bonding member 250E and deterioration of the first polarizing plate 120 or the second polarizing plate 220 due to the components of the adhesive layer of the bonding member 250E. can be suppressed. As a result, it is possible to suppress deterioration in the quality of the display image.

In this embodiment, the end of the bonding member 250E on the first gate FPC 105 side is positioned inside the end of the first polarizing plate 120 and the end of the second polarizing plate 220. However, it is not limited to this. For example, the end of the bonding member 250E on the first source FPC 104 side may be positioned inside the end of the first polarizing plate 120 and the end of the second polarizing plate 220. Both the end of the first gate FPC 105 side of 250E and the end of the first source FPC 104 side of the bonding member 250E (that is, all the ends) are the ends of the first polarizing plate 120 and the ends of the second polarizing plate 220. It may be configured so as to be located inside.

Further, in the present embodiment, at the ends of the first display panel 100 and the second display panel 200, the end (P _OCA ) of the bonding member 250E is located inside the first peripheral light shielding layer 115 of the first liquid crystal cell 110. and the inner edge (P _BM2 ) of the second peripheral light shielding layer 215 of the second liquid crystal cell ₂₁₀ .

With this configuration, when the display screen of the liquid crystal display device 1E is viewed obliquely, it is possible to prevent the end portions of the display image from appearing to have poor image quality.

Further, in the present embodiment, in the end portions of the first display panel 100 and the second display panel 200, the end portion ( _POCA ) of the joint member 250E is the inner end portion of the first bezel portion 611 of the upper frame 610. (P _FR ) and the inner edge (P _FR ) of the second bezel portion 621 of the middle frame 620 . In other words, the end (P _OCA ) of the joint member 250E is positioned outside the opening end of the first bezel portion 611 of the upper frame 610 and the opening end of the second bezel portion 621 of the middle frame 620 .

With this configuration, it is possible to further suppress the appearance of poor image quality at the edges of the display image when the display screen of the liquid crystal display device 1E is viewed obliquely. As an example, the distance L1 from the inner edge (P _BM1 ) of the first peripheral light shielding layer 115 of the first liquid crystal cell 110 to the edge (P _FR ) of the upper frame 610 is 2.52 mm.

Further, in the present embodiment, in the end portions of the first display panel 100 and the second display panel 200, the end portion ( _POCA ) of the bonding member 250E is located outside the first sealing member 114 of the first liquid crystal cell 110. and the outer edge (P _SL2 ) of the second sealing member 214 of the second liquid crystal cell ₂₁₀ .

With this configuration, it is possible to prevent the joining member 250E from becoming unnecessarily long. Air bubbles can be prevented from entering between the panel 200 and the joining member 250E. As a result, it is possible to further suppress deterioration in the quality of the display image.

Note that this embodiment may be applied to the first and second embodiments. In other words, the present embodiment can also be applied when the joint member 250E has a three-layer structure including three joint layers. Further, when the joint member 250E has a three-layer structure, the end portions of the three joint layers may be shifted stepwise.

(Other modifications)
As described above, the liquid crystal display device according to the present disclosure has been described based on the first to third embodiments, but the present disclosure is not limited to the above embodiments.

For example, in Embodiments 1 and 2, the bonding members 250, 250A, 250B, 250C, and 250D are composed of three bonding layers. may

Further, in Embodiments 1 to 3 above, when the first display panel 100 and the second display panel 200 are joined by the joining member, the joining member is attached to the second display panel 200, and then the first display panel 100 is attached. are pasted together, but the present invention is not limited to this. That is, the joining member may be attached to the first display panel 100 and then the second display panel 200 may be attached.

In addition, forms obtained by applying various modifications that a person skilled in the art can think of to the above embodiments and modifications, and arbitrarily combining the components and functions in the embodiments and modifications within the scope of the present disclosure The present disclosure also includes a mode realized by

1, 1A, 1B, 1C, 1D, 1E liquid crystal display device 100 first display panel 101 first image display area 102 first source driver 103 first gate driver 104 first source FPC
105 first gate FPC
106 first circuit board 110 first liquid crystal cell 111 first TFT substrate 112 first opposing substrate 113 first liquid crystal layer 114 first sealing member 115 first peripheral light shielding layer 120 first polarizing plate 121 first polarizing plate on the bonding side 121a , 221a polarizer 121b, 221b light diffusion adhesive layer 122 first polarizing plate on the non-bonding side 200 second display panel 201 second image display area 202 second source driver 203 second gate driver 204 second source FPC
205 second gate FPC
206 second circuit board 210 second liquid crystal cell 211 second TFT substrate 212 second counter substrate 213 second liquid crystal layer 214 second sealing member 215 second peripheral light shielding layer 220 second polarizing plate 221 second polarizing plate on the bonding side 222 Second polarizing plate on non-joining side 250, 250A, 250B, 250C, 250D, 250E Joining member 251, 251C First joining layer 252, 252C Second joining layer 253 Third joining layer 253C Intermediate layer 300 Backlight 310 LED
320 transparent substrate 330 optical sheet 340 reflector 410 first timing controller 420 second timing controller 430 image processing section 600 frame 610 upper frame 611 first bezel section 612 first side wall section 620 middle frame 621 second bezel section 622 second side wall Part 630 Lower frame 631 Body part 632 Support part

Claims (7)

a first display panel having a first liquid crystal cell and a pair of first polarizing plates sandwiching the first liquid crystal cell;
a second display panel having a second liquid crystal cell and a pair of second polarizing plates sandwiching the second liquid crystal cell;
a bonding member that bonds the first polarizing plate of the first display panel and the second polarizing plate of the second display panel;
Of the pair of first polarizing plates, the first polarizing plate on the bonding side bonded to the bonding member has a first polarizer and a first light diffusion adhesive layer,
The first light diffusion adhesive layer is arranged between the bonding member and the first polarizer,
Of the pair of second polarizing plates, the second polarizing plate on the bonding side bonded to the bonding member has a second polarizer and a second light diffusion adhesive layer,
The second light diffusion adhesive layer is arranged between the bonding member and the second polarizer,
At the ends of the first display panel and the second display panel, the ends of the joining member are positioned inside the ends of the first polarizing plate and the ends of the second polarizing plate ,
The bonding member includes a first bonding layer bonded to the first polarizing plate, a second bonding layer bonded to the second polarizing plate, and positioned between the first bonding layer and the second bonding layer. and a third bonding layer,
At the end of the joining member, the end of the first joining layer and the end of the second joining layer are displaced,
The edge of the first bonding layer, the edge of the third bonding layer, and the edge of the second bonding layer are located inside or outside in this order,
Liquid crystal display. The first liquid crystal cell has a first peripheral light shielding layer formed in a peripheral area of the first image display area,
The second liquid crystal cell has a second peripheral light-shielding layer formed in a peripheral area of the second image display area,
At the edges of the first display panel and the second display panel, the edge of the joining member is outside the inner edge of the first peripheral light-shielding layer and the inner edge of the second peripheral light-shielding layer. is located in
The liquid crystal display device according to claim 1. a first frame having a first bezel portion covering the peripheral portion of the first display panel;
a second frame having a second bezel portion covering the peripheral portion of the second display panel;
In the end portions of the first display panel and the second display panel, the end portions of the joint members are located outside the inner end portions of the first bezel portion and the inner end portions of the second bezel portion. are doing,
The liquid crystal display device according to claim 1. The first liquid crystal cell has a pair of first substrates and a first sealing member that seals the first liquid crystal layer between the pair of first substrates,
The second liquid crystal cell has a pair of second substrates and a second sealing member that seals the second liquid crystal layer between the pair of second substrates,
In the end portions of the first display panel and the second display panel, the end portion of the joining member is inside the outer end portion of the first sealing member and the outer end portion of the second sealing member. is located in
The liquid crystal display device according to claim 1. hardness of the first bonding layer and the second bonding layer is higher than hardness of the third bonding layer;
The liquid crystal display device according to any one of claims 1 to 4 . hardness of the third bonding layer is higher than hardness of the first bonding layer and the second bonding layer;
The liquid crystal display device according to any one of claims 1 to 4 . The thickness of the third bonding layer is thicker than the thickness of the first bonding layer and the thickness of the second bonding layer,
The liquid crystal display device according to any one of claims 1 to 6 .

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